Clearing your cache erases the keys on Apple products, which will lock you out of your account if you do not have a recovery phrase in place.
If you do have the recovery phrase, you can recover your account using these steps:
- In the identity.ic0.app click "Lost access and want to recover."
- You’ll then have to enter your identity anchor.
- And then your recovery phrase, which will log you in.
- Once you’re in the management screen, you’ll be able to delete the now-defunct device and add a new device.
Make sure to avoid clearing your cache in the future.